Enzymes utilization in Brewing Industry
Here, the main starting material is malt, produced by allowing barley seeds to germinate under moist conditions. The reserve starch is broken down by the amylase present to give, among other products, glucose and maltose. The grains may then be roasted to prevent further growth and to add flavour, after which the soluble material present is extracted by water to produce the wort. This is then acted upon by the yeast to produce ethanol by alcoholic fermentation of the glucose and maltose.
Bacterial α-amylase (from Bacillus subtilis), which is even more heat stable than wheat α-amylase, is of increasing importance in the brewing industry. In the industrial production of glucose from starch, the latter is first solubilized and partly degraded by bacterial α-amylase and then treated with fungal amyloglucosidase. Glucose may also be obtained from cellulose-containing waste products by treatment with cellulose; as a further possibility, it may be produced together with galactose by the action of β-galactosidase (lactase) on lactose, which is present in whey and so is a major by-product of cheese manufacturing.